Score : 200 points
Snuke has N integers. Among them, the smallest is A, and the largest is B. We are interested in the sum of those N integers. How many different possible sums there are?
Input is given from Standard Input in the following format:
N A B
Print the number of the different possible sums.
4 4 6
5
There are five possible sums: 18=4+4+4+6, 19=4+4+5+6, 20=4+5+5+6, 21=4+5+6+6 and 22=4+6+6+6.
5 4 3
0
1 7 10
0
1 3 3
1